Stopper, motor, and disk drive apparatus

Abstract

A motor includes a stator and a rotor including a disk portion, a cylindrical portion, and a stopper. The stopper includes a stopper protruding portion and is fixed to an inner surface of the cylindrical portion. The cylindrical portion includes a cylindrical portion protruding portion that opposes an outer surface of the stopper. Adhesive is included between the cylindrical portion and the stopper. A gap between an upper end portion of the outer surface of the stopper and an inner peripheral surface of the cylindrical portion protruding portion defines a first tapered gap. A gap between a lower end portion of the outer surface of the stopper and an inner peripheral surface of the cylindrical portion defines a second tapered gap. The adhesive is included in the first tapered gap and the second tapered gap. The stator includes an annular or substantially annular surface below the second tapered gap.

What is claimed is: 
     
       1. A motor comprising:
 a stator; and 
 a rotor which is arranged to rotate relative to the stator about a center axis as a center; wherein 
 the rotor includes:
 a disk portion; 
 a cylindrical portion which extends downward in an axial direction from the disk portion; and 
 a stopper that is cylindrical or substantially cylindrical, is disposed on an inner side in a radial direction of the cylindrical portion and is fixed to an inner surface of the cylindrical portion; 
 
 the cylindrical portion includes a cylindrical portion protruding portion which protrudes inward in the radial direction and opposes an outer surface of the stopper in the radial direction; 
 the stopper includes a stopper protruding portion which protrudes outward in the radial direction, opposes the inner surface of the cylindrical portion, and opposes the cylindrical portion protruding portion in the axial direction; 
 an adhesive is included between the cylindrical portion and the stopper; 
 a gap in the radial direction between an upper end portion of the outer surface of the stopper and an inner peripheral surface of the cylindrical portion protruding portion defines a first tapered gap in which a gap in the radial direction widens upward in the axial direction; 
 a gap in the radial direction between a lower end portion of the outer surface of the stopper protruding portion and an inner peripheral surface of the cylindrical portion defines a second tapered gap in which a gap in the radial direction widens downward in the axial direction; 
 the adhesive is included in at least a portion of the first tapered gap and in at least a portion of the second tapered gap; 
 the stator includes an annular surface that widens in the radial direction; and 
 the annular surface is positioned below the second tapered gap and the second tapered gap opposes the annular surface in the axial direction. 
 
     
     
       2. The motor according to  claim 1 , wherein
 the inner peripheral surface of the cylindrical portion protruding portion which opposes in the radial direction the upper end portion of the outer surface of the stopper includes a tilted surface that is tilted with respect to the center axis; and 
 the tilted surface includes:
 a first tilted portion that is tilted with respect to the center axis; and 
 a second tilted portion having a tilt angle with respect to the center axis, which is greater than that of the first tilted portion. 
 
 
     
     
       3. The motor according to  claim 1 , wherein a portion of the adhesive is disposed on an upper side in the axial direction rather than the first tapered gap. 
     
     
       4. The motor according to  claim 1 , wherein an end portion of the cylindrical portion protruding portion which opposes the stopper includes a tilted surface or a curved surface. 
     
     
       5. The motor according to  claim 1 , wherein a tip end portion of the cylindrical portion includes a tilted surface or a curved surface of which a space in the radial direction from the center axis increases downward in the axial direction. 
     
     
       6. The motor according to  claim 1 , wherein the cylindrical portion protruding portion includes a flat surface that is parallel or substantially parallel to the center axis. 
     
     
       7. The motor according to  claim 1 , wherein a concave portion that is recessed outward in the radial direction is disposed in a portion where the cylindrical portion protruding portion is connected to the inner surface of the cylindrical portion. 
     
     
       8. The motor according to  claim 1 , wherein a tilted surface or a curved surface of which a space in the radial direction from the center axis increases downward in the axial direction is defined in a portion of the outer surface of the stopper which opposes the cylindrical portion protruding portion. 
     
     
       9. The motor according to  claim 1 , wherein the stopper protruding portion includes a flat surface that is parallel or substantially parallel to the center axis. 
     
     
       10. The motor according to  claim 1 , wherein the stopper protruding portion includes a tilted surface or a curved surface of which a space in the radial direction from the center axis decreases downward in the axial direction. 
     
     
       11. The motor according to  claim 1 , wherein at least any one of end portions on a lower side in the axial direction and on an upper side in the axial direction of the stopper is parallel or substantially parallel to the disk portion. 
     
     
       12. The motor according to  claim 1 , wherein the cylindrical portion protruding portion includes a surface that is parallel or substantially parallel to the stopper protruding portion. 
     
     
       13. The motor according to  claim 1 , wherein
 the stator includes a bearing mechanism which supports the rotor; and 
 an inner surface of the stopper is positioned on an inner side in the radial direction rather than an end portion on an outer side in the radial direction of the bearing mechanism. 
 
     
     
       14. The motor according to  claim 13 , wherein a portion of the adhesive opposes the bearing mechanism in the radial direction. 
     
     
       15. The motor according to  claim 13 , wherein a portion of the stopper opposes the bearing mechanism in the axial direction. 
     
     
       16. The motor according to  claim 1 , wherein a cross-sectional area of the second tapered gap in the axial direction is greater than a cross-sectional area of the first tapered gap. 
     
     
       17. The motor according to  claim 1 , wherein the cylindrical portion is integrally provided with the disk portion as a single monolithic member. 
     
     
       18. The motor according to  claim 1 , wherein
 the disk portion includes at least one through-hole or concave portion; 
 the cylindrical portion includes a convex portion corresponding to the through-hole; and 
 the convex portion is disposed in the through-hole or the concave portion. 
 
     
     
       19. The motor according to  claim 18 , wherein the convex portion is disposed in the through-hole or the concave portion, and the cylindrical portion is fixed to the disk portion by at least any one of press-fitting, caulking, adhesion, and welding. 
     
     
       20. The motor according to  claim 1 , wherein the cylindrical portion is fixed to the disk portion by welding. 
     
     
       21. A disk drive apparatus comprising:
 the motor according to  claim 1 ; 
 at least one sheet of disk mounted to the rotor; and 
 a housing which accommodates the motor and the disk.